Back around Black Friday, the good folks at Steam were having a series of incredible sales. One such sale was a bundle of independent games for life $5. One of the games in said bundle was World of Goo by 2D Boy. I've just finished (most) of this ridiculously addicting ridiculous game and I know I'll be revisiting it soon.
The premise is simple: there is living goo balls and you have to build structures to solve puzzles. Usually these puzzles involve building a lattice-structure to a pipe that will suck up the loose goo balls that skitter along the lattice. But many of these puzzles are anything but simple. You have to do some out-of-the-box thinking to figure out how to build bridges, towers, or dangling chains of . . . well, I think it's supposed to be spit to get to your goal.
The game itself is short, just five quick chapters, but like I said, I know I'll be back to replay the levels. Part of this is to try for the "OCD" badges, namely to finish the levels while achieving a difficult feat (i.e. rescuing so many extra goo balls, completing it in so many moves or within so much time). Plus there's also the tower building mini-game. You can use goo balls that you've rescued to build a tower. Supposedly there's a meta-game that you can eventually reach. I haven't gotten close yet, but I'll keep trying.
If you're interested in trying it out, you can purchase it via Steam here. Trust me, it's worth every penny.